1. Field of the Invention
The present invention relaters to a vibration-type driving unit, as well as a two-dimensional driving apparatus, an image-blur correction apparatus, an interchangeable lens, an image capturing apparatus, or an automatic stage including the vibration-type driving unit.
2. Description of the Related Art
Great many vibration-type driving units that excite vibrations in a vibrator to move a moving body that is in pressure-contact therewith have been proposed.
They are positioned as important functional components particularly in optical devices which are required to operate accurately. An example thereof is a two-dimensional driving apparatus including a plurality of linear vibration-type driving units (a type capable of linearly moving a moving body), in which the driving operations thereof are combined, allowing two-dimensional movement of the moving body.
Another known example is an image-blur correction apparatus using this two-dimensional driving apparatus (for example, Japanese Patent Laid-Open No. 2012-44832).
However, the method of combining driving operations of a plurality of vibration-type driving units has the following problems to be solved.
For example, the moving direction of the moving body and the driving direction of some of the plurality of vibration-type driving units sometimes intersect at right angles or at angles close to right angles depending on the moving direction of the moving body.
In this case, not only the vibration-type driving unit whose driving direction intersects the moving direction at right angles or angles close to right angles cannot contribute to driving, but also a frictional force due to the contact between the moving body and the vibration-type driving unit exerts a load on the movement of the moving body to cause an energy loss, resulting in an output loss.
This may cause a decrease in characteristics when used as, for example, a two-dimensional driving apparatus, an image-blur correction apparatus, an interchangeable lens, an image capturing apparatus, or an automatic stage.
To solve these problems, Japanese Patent Laid-Open No. 2012-44832 discloses a configuration having a moving mechanism (a deflecting mechanism) that allows a vibrator to move in a direction (a deflecting direction) intersecting the driving direction.
Therefore, the vibrator and the moving body are configured not to move relative to each other in the deflecting direction.
By forming the deflecting mechanism with a guide mechanism having a remarkably small sliding loss or an elastic spring having low rigidity, a load that acts on the moving body can be made extremely small. This remarkably reduces the output loss.
However, the output-loss reduction unit for the vibration-type driving unit, the two-dimensional driving apparatus, or the image-blur correction apparatus described above mainly has the following problems.
The first problem is that the occupied space is large.
In the related art example described above, a component in contact with the vibrator is moved in the driving direction of the vibration-type driving unit by the vibration of the fixed vibrator, thereby moving the moving body fixed thereto.
To allow a predetermined amount of movement of the moving body, the sum (length) of the dimension (length) of the component in contact with the vibrator and the amount of movement (moving distance) thereof is needed as an occupied space (length), thus increasing the size of the apparatus.
Another problem is that unnecessary vibrations are prone to occur in the component in contact with the vibrator.
Unnecessary vibrations make the state of contact between the vibrator and the component in contact with the vibrator unstable, leading to unstable output.